A known image forming apparatus includes a sheet supply tray configured to be attached to and removed from a main body. In the image forming apparatus, when the sheet supply tray is located at an outside position, a stopper of the main body engages a protrusion of the sheet supply tray to restrict removal of the sheet supply tray from the main body. When the sheet supply tray is removed from the main body, a rear portion of the sheet supply tray is lifted such that the protrusion moves over and out of engagement with the stopper, and the sheet supply tray can be removed from the main body. When the sheet supply tray is attached to the main body, the rear portion of the sheet supply tray is lifted such that the protrusion moves over the stopper to be inserted into the stopper, and the sheet supply tray can be attached to the main body.